Improvement in furnace-doors



D. AU LD, .|r.

Furnace-Doors. l

v Patented Dec.16,1873.

FIGA. l FIG-2.

UNITED STATES PATENT OFFICE.

DAVID AULD, JR., or eLAseow, NORTH BRITAIN.

IMPROVEMENT IN FuRNAcE-DooRs.

Specification forming part of Leiters Patent No. 145,608, dated December 1G, 1873; application filed May 6, 1873.

To all whom it may concern:

. Be it known that I, DAVID AULD, Jr., of Glasgow, in the county of Lanark, North Britain, have invented Improvements in Furnace-Doors and in apparatus connected therewith, of which the following is a spe `ica tion:

rIhis invention consists of a selfacting- .of a furnace-door, adapted for regulating the supply of air for burning the products of co1nbust-ion in the furnace, and showing one modi ication of my said invention, whereby the regulator B is constituted self-acting, applied thereto. Fig. 2 represents an elevation of that end of the door Inarked A in Fig. 1, while Fig.3 is aplan of the same. 0n these iigures the apparatus is shown in the position which it occupies when the door A is shut. Fig. 4. is an elevation of that end of the door marked B, Fig. 1, and shows the position of the apparatus when the door A is open.

The air regulator B is furnished with a sandbox, C; and on one end of the axis D of the air-regulator and sand-box, a crank, E, is fixed, to which the upper end of a rod, F, is coupled. The rod F passes down through a guide, G, fixed to the lower part of the door A, and its lower extremity is formed to carry a roller, H, which revolves on a pin or stud, b. The periphery of the roller II bears upon an inclined plane or edge, formed, in this in stance, by securing to the frame of the door or other stationary part of the apparatus, a bent arm or bar, I, and when the door is Vopened the rollerv H revolves or rolls up the inclined arm I, thereby pushing the rod F upward and turning the crank E through a sufficient arc to invert the air-regulator B, as shown at Fig. 4. When the air-regulator B has been thus inverted, the sand in thelower part of the box C falls into the hopper J situated at the upper end of the box, as more particularly seen at Fig. 1, so that on again shutting the door A, there is a sufficient weight of sand in the hopper J to keep the air-regulator B open in the position shown in dotted lines at Fig. 2. The hopper J is provided with an opening, c, at its lower end, through which the sand (on the door being shut) falls slowly back into the lower part of the box C, and thereby gradually `closes the air-regulator B.

By this means the regulator B is kept open for a length of time sufficient to admit the quantity of air requisite to burn the smoke and gaseous products evolved from the charging of green coal into the furnace.

In lieu of arranging the coupling-rod F, guide G, and inclined arm I, hereinbefore described, at the lower side of the furnace-door, as shown at Figs. 1, 2, 3, and 4 of the drawings, the said rod F, guide Gr, and inclined arm I may be arranged at the upper side of the furnace-door, as shown in front elevation at Fig. 5, and in end elevation at Fig. 6 of the drawings, or they'may be arranged at some other convenient part thereof, and in place of providing the rod F with a roller, as shown on the several gures of the appended drawings, the rod F may be formed with a loop, which, as the furnacedoor is opened, slides up the inclined arm I, and inverts the air-regulatorB through the intervention of the crank E, as hereinbefore described.

In lieu of placing the crank E at the outer side of the bearing K of the axis or spindle D, as shown on the drawings, it may be situated at the inner side of the said bearing, if desired.

I claimy 1. A door for furnaces provided with a damper and with a sand-box connected to the damper,-

and closing the same as the sand descends in the box, for the purpose speciiied.

2. The combination of an inclined bar and rod with the door, damper, and sand-box, as and for the purpose described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

DAVID AULD, Jn. Witnesses:

JOHN BROWN, JOHN C. MAGANDIE. 

